“The last person must have set it up that way.”
“The last person wrote that code.”
“The last person just didn’t configure it right.”
You can use that excuse for 6 months.
For six months, you’re allowed to get up to speed on the company’s politics, the intricacies of the app, and the responsibilities of different departments. You’re allowed to prove yourself to your peers, building up social capital so that they’ll take your recommendations and run with ’em..
You can take your time figuring out whether the last person knew what they were doing or not. You should start